Comparison between the integrated Hα profiles of the whole nebula (bottom) and the profile of the kinematical core (r ≤ 25 pc) and that of the kinematical halo (r > 25 pc). The blue points are the data and the thick-dashed red line is the fit of two Gaussian components shown in thin red. The single-Gaussian fit is shown by the black line. The parameters of these components, observed and corrected for instrumental and thermal broadening, are shown in the legend.